When Keeping Up With the Kardashians debuted on E! in 2007, Kendall was only 11 and Kylie was 9. Now, at 16 and 14, respectively, they’re not only gorgeous — they’ve got the magazine covers to prove it — but they’re kindhearted as well.

For example, at Kendall’s sweet 16 last November, all gifts were donated to a children’s hospital.

To honor the terrific twosome, Celebuzz has compiled a gallery of old school — and new — photos of them.